The invention is related to a hand machine tool, such as a drill, having a locking chuck. A percussion drilling device with drill chuck which is suitable for hand machine tools is disclosed in German Patent Publication DE-C 35 16 451, its adjusting ring for the chuck jaws being secured against rotation by means of a sleeve during operation. The sleeve must be drawn back and locked in order to adjust the chuck jaws. If the user forgets to disengage the lock before operating the tool, the means for securing against rotation are not effective, the chuck jaws can move back and the tool becomes loose during the percussion drilling.